Members of the Polynesian Voyaging Society on the voyaging canoe Hokulea, on its 47,000 nautical mile journey over four years to engage a global community in creating a healthy and sustainable planet, arrive in Sydney on May 19, 2015. Hawaiis Ho¯ku¯le?a sailed into Sydney Harbor as part of its worldwide conservation themed Malama Honua voyage, a voyage in which the 19-meter vessel sails using only wind power and is navigated using ancestral knowledge of star patterns, ocean movement and weather patterns. (Peter Parks/AFP/Getty Images)

Crews used no modern navigational instruments during the boat's circumnavigation.

You could call the voyage of the Hokulea around the world in 1,095 days.

According to the Associated Press, the Polynesian voyaging canoe, which was manned on a number of separate legs by a crew of about 12, completed a three-year journey around the world using no modern navigational instruments.

As the AP noted, the boat’s crew “relied only on their understanding of … ocean swells, stars, wind, [and] birds … to sail across about 40,000 nautical miles to 19 countries.”

Thirty-eight-year-old apprentice navigator Ka’iulani Murphy said the most difficult aspects of guiding the traditional canoe were dealing with cloud cover and keeping the two-hulled canoe from speeding away from its boat escort.

Its crew slept on waterproof covered–plywood bunks and ate fish caught along the way, per the AP.

The boat entered Hawaiian waters off the coast of Oahu this past Saturday.